A physician can use a trocar device to deliver fluid into a body cavity during specific medical procedures or treatments. The purpose of using such a device is to inflate or distend the body cavity to allow the surgeon (1) exploration of the area in which the surgery will be performed and (2) to provide a view of the site to be treated or observed. Insufflation is used in many common procedures including endoscopic surgical procedures, laparoscopic procedures performed on the abdominal cavity and thoracoscopic procedures performed on the chest cavity.
At the beginning of the procedure, the surgeon cuts an incision to traverse the skin and tissue layers until the body cavity is opened. A Verres need is inserted to start insufflation. A Verres needle may be used, however a trocar can be placed directly without use of a needle to enter the body cavity. An external, pressurized fluid source is connected to the needle. The fluid flows from the proximal end of the needle to a distal end thereof from which the fluid exits and is delivered into the body cavity. This causes the tissue layers to distend, a process known as insufflation. Carbon dioxide gas is commonly used for insufflation and other substances, which may include drugs and anesthetics may be mixed with the carbon dioxide gas and administered simultaneously.
After satisfactory insufflation, the needle is removed and a trocar sleeve may be inserted through the incision and into the body cavity. Trocar sleeves are sized and shaped to pass through the incision and tissue layers of a body so that the sleeve penetrates at least partially into the body cavity. Cameras and/or surgical devices may be inserted into the sleeve to provide the surgeon with a view of the surgical site or to allow the surgeon to treat the area.
My U.S. Pat. No. 6,733,479 discloses, a trocar sleeve with a plurality of apertures that address the problem of the “jet streaming effect” and is hereby incorporated by reference. The “jet streaming effect” is known to damage tissues and/or organs of the body because as the fluid contacts those surfaces, the lining of the body cavity and the surfaces of the organs housed therein undergo severe heat loss. The effect is more fully described in U.S. Pat. No. 6,733,479 and references cited therein. To eliminate or reduce the “jet streaming effect” my prior patent discloses a series of apertures located along the trocar sleeve to effectively distribute the gases at velocities, which are below the threshold of the “jet streaming effect”. While the perforated trocar greatly reduces or eliminates the “jet streaming effect” there can be transient conditions when an instrument can periodically obstruct the trocar sleeve and therefore temporarily affect the fluid flow through the trocar sleeve and possibly cause localized regions on the trocar sleeve where the “jet streaming conditions” could occur. For example, a manipulation of an instrument such as surgical device within the trocar sleeve or the insertion of an irregular shaped instrument might block off a substantial portion of the trocar sleeve thereby increasing velocity at other regions of the trocar sleeve until the jet streaming velocity is exceeded. Since this condition is most likely to occur in a localized area and might be only a temporary condition the user might not even know that a “jet streaming condition” is occurring at some of the apertures in the trocar sleeve.
The present invention provides a solution to the problem of transient conditions that can produce localized “jet streaming conditions” by providing a trocar sleeve that does not produce a “jet streaming condition” even though different size and shape instruments are inserted into the trocar sleeve. Furthermore, the instruments can be manipulated in the trocar sleeve without fear of inducing a localized “jet streaming condition”. A further embodiment of the invention eliminates the “jet streaming condition” through eliminating of instruments in the trocar sleeve that is used to deliver fluids to a body cavity.
The present invention is a trocar sleeve for insufflating the body cavity without damaging a tissue in the body cavity due to transient flow conditions. More specifically, the invention includes a trocar having a fluid flow chamber that delivers an insufflating fluid at a velocity below a jet streaming velocity whether or not an instrument such as a camera or a surgical device is in the lumen in the trocar sleeve. In one embodiment a double walled trocar sleeve is used to inhibit or prevent the “jet streaming condition” and in another embodiment a blind trocar sleeve is used to inhibit or prevent the “jet streaming condition”. In both embodiments, the invention provides a fluid flow condition that is not affected by instruments.